1. Field of the Invention
This invention relates to winders of the type employed in the paper, plastics, nonwoven and textile industries to wind web material into large rolled packages, and is concerned in particular with an improved surface winder for continuously winding such materials into a succession of packages.
2. Description of the Prior Art
In the conventional continuous surface winder, the winding operation commences at a first winding station where the web material begins to accumulate in a rolled package around a tubular core of cardboard or other like material. A mandrel is removably inserted in the core, and a so-called "rider roll" is yieldably applied to the package to stabilize the initial phase of the winding operation at the first Winding station. The winding operation continues as the package is shifted laterally along a transfer path from the first winding station to a second winding station. The winding operation is completed at the second winding station under the stabilizing effect of a second rider roll.
During its transfer from the first winding station to the second winding station, the package is carried on a plurality of rotatably driven winding drums which extend between rigid side frames in a cross machine direction perpendicular to the transfer path. The package is not stabilized by a rider roll during its transfer between winding stations. The ends of the mandrel protrude from opposite ends of the core, and are axially confined between wear plates fixed to the side frames. A first pivotal "hold down" mechanism yieldably urges the ends of the mandrel downwardly at and during transfer away from the first winding station. A second hold down mechanism is employed at the second winding station. At the conclusion of a winding operation, the web material is severed, the severed leading end is automatically applied to a fresh core at the first winding station, and the completed package of wound web material is cleared from the second winding station, as winding continues uninterruptedly at the first winding station.
Although conventional continuous surface winders operate in a generally satisfactory manner, the resulting edge profile of the rolled package sometimes lacks uniformity. Investigations have revealed that edge nonuniformity can be attributed to a number of factors, including axial drift of the supporting mandrels between misaligned non-parallel wear plates, binding of the mandrel ends between the wear plates during transfer between the winding stations, unacceptable variations in the nipping force with which the package is held against the winding drums, the absence of the stabilizing effect of a rider roll during transfer of the package between the first and second winding stations, and an interruption of hold down forces during the "hand off" from the first hold down mechanism to the second hold down mechanism.
The objective of the present invention is to overcome the inherent limitations and deficiencies of conventional continuous surface winders, thereby making it possible to substantially improve the edge profiles of the resulting rolled packages.